Nora Ephron: 'Be the heroine of your life, not the victim.' Photograph: Linda Nylind for the Guardian

Dry skin. Email. Panels on "Women in Film". These are just some of the things the great and, unbelievably, now late Nora Ephron included in her list of "Things I won't miss" in her last collection of essays, the mortality-tinged I Remember Nothing. Unfortunately for the rest of us, it's a list that serves as a reminder of how much Ephron herself will be missed.

For a start, it sounds a little like a whistlestop tour of topics that have featured in Ephron's five decades-long career as a journalist, screenwriter and essayist. Few people wrote about body insecurities as shrewdly and hilariously as Ephron, from the smallness of her breasts in her 1972 essay A Few Words About Breasts, included in the collection Crazy Salad ("My girlfriends, the ones with the nice big breasts, would go on endlessly about how their lives had been far more miserable than mine … I have thought about their remarks, tried to put myself in their place, considered their point of view. I think they are full of shit") to the amount of effort a woman needs to put into looking vaguely decent in On Maintenance, from her 2006 collection of essays I Feel Bad About My Neck.

Email, of course, was the plot motor in You've Got Mail, one of several comedies she wrote starring Meg Ryan, and the combination of these two women briefly resuscitated the kind of smart screwball comedies the US film industry hadn't produced since the days of Rosalind Russell and Katharine Hepburn.

Ephron made a huge contribution to film, but there was nothing po-faced, nothing "panels on 'Women in Film'" about it. She was, after all, a feminist who satirised the overly solemn and self-defeating aspects of feminism, such as Betty Friedan's baffling determination to start fights with Gloria Steinem. And there was her unforgettable description of a women's consciousness group in her 1972 essay, Vaginal Politics, also from Crazy Salad: "We have lived through the era when happiness was a warm puppy, and the era when happiness was a dry martini, and now we have come to the era when happiness is 'knowing what your uterus looks like'."

Not all her movies were great but even if she'd just written When Harry Met Sally her reputation would have been assured, never mind Silkwood, Heartburn, Julie & Julia and Sleepless in Seattle. While I have to confess that I disagree with the central tenet of When Harry Met Sally – despite what Harry says, men and women can be friends; the sex part does not always get in the way – it is next to impossible to think of five other movies made in the past 30 years with dialogue as crackingly smart and jokes as weepingly hilarious, and it is flat-out impossible to think of an 80s movie that has dated so little. If When Harry Met Sally came out tomorrow it would be applauded as a breath of life to modern comedies.

Ephron described writing that screenplay in a 2010 essay in the New Yorker, My Life as an Heiress: "I was just doing it for the money and, face it, it was never going to be made, and, besides, it was really hard. I switched off the computer," she writes at one point. However, at the end of the essay, realising that she is not, contrary to expectations, going to come into the inheritance that she thought would get her out of this "really hard" screenplay, "I went back upstairs and turned on my computer and went back to work … I am quick to draw lessons from my own experiences and the lesson I drew from this one was that I was extremely lucky not to have inherited real money, because I might not have finished writing When Harry Met Sally, which changed my life."

Good writing is, of course, very difficult to pull off and excellent writing is, I have heard, absolute agony but, naively, I was amazed when I read that article: When Harry Met Sally was difficult for Ephron to write? But it's so effervescent! How could something that includes dialogue such as the following have been drudgery to produce when it sounds so light and effortless?

Harry: I've been doing a lot of thinking and the thing is, I love you.

Sally: What?

Harry: I love you.

Sally: How do you expect me to respond to this?

Harry: How about, you love me too.

Sally: How about, I'm leaving.

Or this:

Sally: Is he seeing anyone?

Marie: He was seeing this anthropologist.

Sally: What's she look like?

Marie: Thin. Pretty. Big tits. Your basic nightmare.

Or even:

Sally: So what do you do with these women, you just get up out of bed and leave?

Harry: Sure.

Sally: Well, explain to me how you do it. What do you say?

Harry: You'd say you have an early meeting, early haircut or a squash game.

Sally: You don't play squash.

Harry: They don't know that, they just met me.

Sally: That's disgusting.

Harry: I know, I feel terrible.

Sally: You know, I'm so glad I never got involved with you. I just would've ended up being some woman you had to get up out of bed and leave at three o'clock in the morning and clean your andirons, and you don't even have a fireplace. Not that I would know this.

Honestly, the only thing funnier than When Harry Met Sally is the fact that the writer of Dead Poets Society – Dead Poets Society! – beat her to the Oscar that year.

But Ephron was always refreshingly honest about how goddamn hard she had to work to be so good ("It takes a huge amount of will and energy for anything to happen to you," she once said) and how hard women especially have to work. Yes, she was born into a decidedly privileged world, with screenwriter parents who regularly entertained the most extraordinary A-listers in their front room, but Ephron made it all on her own, through talent, certainly, but also fierce, uncowed work. In 1996, she gave the commencement address at her alma mater, Wellesley College, that reads less like a simple speech than a call to arms: "Don't let the New York Times article about the brilliant success of Wellesley graduates in the business world fool you – there's still a glass ceiling. Don't let the number of women in the workforce trick you – there are still lots of magazines devoted almost exclusively to making perfect casseroles and turning various things into tents … The acquittal of OJ Simpson is an attack on you. Any move to limit abortion rights is an attack on you."

Her essays about what it was like working as a "girl reporter" back in the 60s and 70s are, of course, very funny but with a strong wire of fierceness running through them as she hacks her way up from the mailroom at Newsweek to writing a column about women for Esquire magazine.

Ephron's honesty about her own worries, her own pains, her own anxieties was one of the defining characteristics of her work, particularly as a journalist and essayist. She never slumps into self-pity but rather elevates it all with humour that is tack-smart but accessible, sharp but warm, never self-deprecating (thank God) and always appealing. She wrote about her mother's alcoholism ("She was a cut above the other mothers … None of them had careers and children … Also, she served delicious food … What's more, she dressed beautifully … And then she ruined the narrative by becoming a crazy drunk"); her difficult relationship with Lillian Hellman, and, of course, her flat-out hatred of ageing (in I Remember Nothing, she writes there is only one part of her body she likes now: "the little bare space" on the back of her head).

"My mother taught me many things when I was growing up, but the main thing I learned from her is that everything is copy. She said it again and again, and I have quoted her saying it again and again. As a result, I knew the moment my marriage ended that someday it might make a book – if I could just stop crying," she wrote in 2004, in the updated introduction to Heartburn, the novel based on the end of her marriage to Washington Post reporter Carl Bernstein, and one of my favourite novels from the last century and certainly one of the funniest.

The plot, of both the book and the real-life story on which it was based, are well known: plucky heroine, seven months pregnant and mother of a toddler, discovers that her hotshot reporter husband is flagrantly cheating on her with "an unbelievably tall person" (who, in real life, was, of all people, Margaret Jay), a friend of the heroine, and the husband behaves like a total ass about it. Bernstein, unsurprisingly, was not a fan of the book (nor was Margaret Jay's then husband Peter, who, Ephron wrote in 2004, "to this day constantly takes shots at me for the damage I did to his family. I mean, really!"), but at least he got to be cast as Jack Nicholson in the film whereas, as anyone who has ever seen a photo of Bernstein knows, the resemblance is a lot closer to Dustin Hoffman (who played him in All the President's Men, and quite right, too).

Ephron bristled whenever her book was described as a "thinly disguised novel" ("the words 'thinly disguised' are applied mostly to books by women") and anyway, as she put it, triumphantly and rightly: "One of the things I'm proudest of is that I managed to convert an event that seemed to me hideously tragic at the time to a comedy – and if that's not fiction, I don't know what is." It was, to use another great Ephron quote, the definition of instruction to Wellesley students: "Be the heroine of your life, not the victim."

Yet while her marriage to Bernstein, and the breakdown of it, may have been the more high-profile, it was her next marriage, to Nicholas Pileggi, the screenwriter of Goodfellas and Casino, that gave her the kind of romantic happy ending for which her films became so known.

In her 1972 essay Reunion, she wrote furiously about how the dean of her college once advised her to "devote yourself to your husband and marriage". As if in defiance of that ever since, Ephron seemed to do everything: journalist, author, screenwriter, playwright, director, food connoisseur, wife, mother, the epitome of the well-heeled New Yorker, the woman every woman wished was her best friend, and all with such simple but smart good humour. A sample from her list of things she will miss captures this better than I ever could:

"My kids.

Nick.

The view out the window.

Dinner at home just the two of us.

Dinner with friends.

Dinner with friends in cities where none of us live.

Coming over the bridge to Manhattan.

Pie."

This article contains affiliate links, which means we may earn a small commission if a reader clicks through and makes a purchase. All our journalism is independent and is in no way influenced by any advertiser or commercial initiative. The links are powered by Skimlinks. By clicking on an affiliate link, you accept that Skimlinks cookies will be set. More information.